Resilient Design

PSEG Pier and Revetment Evaluations

Anonymous — ��Ϸ��d, 25 Sep 2019 13:53:53 +0000

PSEG Pier and Revetment Evaluations Anonymous ��Ϸ��d, 09/25/2019 - 09:53

Challenge

The PSEG power generation station site was significantly damaged from the unrelenting pounding, over the course of several days, from Superstorm Sandy in 2012. The oil dock, shore-based infrastructure, and the south facing revetments sustained damage from the 100-year design storm surge and wave action. GZA was retained to perform an assessment of coastal and structural damage.

Solution

GZA performed inspections and studies to document the damage and determine the return period of the storm and the wind and wave characteristics. Design plans (30% design level) and estimates of probable cost were prepared for the repair of the oil dock to its original condition and design and construction of the oil dock to meet current code requirements. Based on these scenarios, GZA provided insight into the permitting requirements and code upgrade requirements.

GZA conducted numerous inspections and studies, including: underwater and topside structural inspection of an unloading dock; assessment of riprap and coastal damage; a wind and wave study to determine environmental loadings for “Sandy�� loading; repair scenarios and estimated costs; permitting requirements for repair and replacement of resources; valuated code requirements for reconstruction and replacement.

Benefit

GZA’s assessment of coastal and structural damage to this important power infrastructure included coastal flood modeling to design flood resistant, replacement marine structures.

Insights

Assessment of Coastal and Structural Damage to Infrastructure
Design Plans for Marine Structures
Coastal Flood Modeling for Design for Flood-Resistant Marine Structures

Connecticut

Transportation & Infrastructure

Water

Energy

Waterfront and Coastal Engineering

Natural Hazard Risk Management, Climate Adaptation and Resilience

Long Wharf Flood Protection Study and Living Shoreline Design

Anonymous — Mon, 23 Sep 2019 14:07:14 +0000

Long Wharf Flood Protection Study and Living Shoreline Design Anonymous Mon, 09/23/2019 - 10:07

Challenge

The Long Wharf area of New Haven, located within FEMA VE and AE high risk flood hazard zones, is highly vulnerable to coastal flooding. It has historically experienced severe flooding and flood damage from hurricanes and extreme weather events dating to the Hurricane of 1938 and more recently during Hurricane Irene and Superstorm Sandy. Improved resilience to coastal flooding is imperative to the social, economic and ecological resilience of the City of New Haven and the region.

Solution

GZA implemented a flood protection study in the Long Wharf District of New Haven. The District consists of two distinct areas in their character and use: the waterfront shoreline and the industrial district. The Long Wharf Flood Protection Study included planning and design of coastal flooding mitigation and shoreline protection measures for the area located northwest of the Long Wharf shoreline to Union Avenue. An inter-disciplinary team led by GZA completed a detailed flood vulnerability analysis in the project area. Based on the results of the vulnerability analysis, the team identified flood control strategies that not only addressed economic concerns related to business disruption after flooding but also identified ways in which the flood mitigation alternatives benefit the general public by creating a visionary plan for the City to improve social, economic, and ecological resilience to sea level rise, local intense precipitation, storm surge, and erosion. GZA’s project team includes Utile, Biohabitats, and Cambridge Systematics.

GZA’s project approach was multidisciplinary, and the team:

Incorporated industry-accepted science for sea level rise and coastal flooding;
Performed statistical analysis on historical storm surge flood level data from relevant water level stations, such as those from National Oceanic and Atmospheric Administration (NOAA);
Used high resolution terrain data (post-Sandy);
Completed high resolution, hydrodynamic computer flood modeling to characterize coastal flooding and its effect on structures and natural features;
Created scenario-based flood maps to evaluate the vulnerability of the area to tides and storm surges;
Managed all information using Esri ArcGIS geographic information system (GIS) software;
Used a “risk-based�� approach, defining coastal flood hazards in terms of probability, consistent with methods currently being used by state and federal agencies; and
Identified resiliency strategies and alternatives that are consistent with City of New Haven’s current vision and plans for development.

The design includes an integrated approach to flood protection, shore protection, and environmental and ecological benefits, including a seawall, a buried revetment, timber walkway, beach nourishment and wetland enhancement, tidal flats, and oyster reef submerged breakwaters. This plan also creates a new level of access and usability of the shoreline by the public.

Benefit

The study identified strategies relevant to the character of the neighborhoods and areas to reduce coastal flooding in the district. It is also used as a road map for the City for creating social, economic, and ecological resilience in relation to future sea level rise impacts, storm surge, and erosion.

GZA’s permit-level design for the proposed Long Wharf Flood and Shoreline Protection project enables the City of New Haven to move forward quickly with final design and construction as funding is secured. The comprehensive analysis and design acknowledges that a resilient New Haven is critical to Connecticut and creates the resiliency features necessary to foster social, economic, and ecological health of the area.

Insights

US HUD CDBG-Disaster Recovery Grant
FEMA Building Resilient Infrastructure and Communities (BRIC) Grant
Review of Existing Plans
Vulnerability and Risk Assessment
Adaptation Options Analysis
Stakeholder Identification and Engagement
Public Information Meetings
Living Shoreline Design
Feasibility Analysis of Flood Mitigation Strategies

Connecticut

Water

Government

Waterfront and Coastal Engineering

Natural Hazard Risk Management, Climate Adaptation and Resilience

Land Use and Environmental Planning

Natural Resources and Ecological Services

Data Management, Analytics and Visualization Solutions

Encore Boston Harbor Resort and Casino

Anonymous — ��Ϸ��d, 18 Sep 2019 18:52:40 +0000

Encore Boston Harbor Resort and Casino Anonymous ��Ϸ��d, 09/18/2019 - 14:52

Challenge

The 32-acre property on the Mystic River selected for the Encore Boston Harbor resort and casino had been impacted by historic chemical manufacturing use; much of the site was on salt marsh that had been filled with waste materials from operations at the site and/or nearby facilities. The buildings on the property were razed in the 1970s and the property had been used primarily as a material storage and staging yard since the mid-1990s, when rock and fine-grained material (“tunnel muck��) from the construction of the Deer Island Outfall project were stockpiled on it and later spread out. In addition, the geologic conditions varied greatly within the site. The combination of complex environmental and geologic conditions, coastal flood vulnerability, the waterfront setting, and the fast-paced nature of this mega-development project required a focused project team with a diverse set of technical skills.

Solution

During initial phases of the project, GZA participated in negotiations with the former owner regarding the extent of remediation warranted by site conditions. GZA also prepared several sections of the reports required by the Massachusetts Environmental Policy Act (MEPA), and developed cost estimates for reaching regulatory closure under the Massachusetts Contingency Plan (MCP) and for dealing with contamination encountered during construction. To meet the growing needs of the project, GZA’s involvement quickly grew to include geotechnical and marine engineering as well as comprehensive natural resources and permitting services.

Ecological Services and Resilient Design: GZA’s natural resources team conducted topographic and hydrographic surveys; performed biological surveys of the shoreline, intertidal, and sub-tidal zones; conducted extensive sediment sampling and analysis to further define the nature and extent of sediment impacts from historic operations; characterized sediments within a former ship channel to identify costs associated with dredging and reopening the channel for the project’s use; and developed plans for a Living Shoreline to return the native salt marsh and native coastal bank plant species to the fringe of the site as part of the environmental impact mitigation for the project.

Geotechnical Engineering: GZA developed geotechnical foundation design recommendations to support the 29-story tower as well as the low-rise portions of the project. With a large portion of the building footprint constructed over a multilevel garage, groundwater control was an important issue for both construction and building design. GZA evaluated foundation, groundwater control, and lateral earth support options, taking into account both the extent and depth of the basement, and both geotechnical and environmental considerations. Given the variety of building loads and subsurface conditions, multiple foundation types were utilized: slurry walls for excavation support and the support of building loads; load-bearing elements to support the tower; precast prestressed concrete piles and drilled mini piles to support low rise portions of the building; a mat foundation for the majority of the below-grade garage; and rock tiedowns to help resist hydrostatic uplift pressures.

Environmental Services: GZA designed and implemented remedial activities to address three highly contaminated areas of the site prior to building construction. In one area, in-situ stabilization was used to help neutralize low-pH groundwater. In two other areas with elevated concentrations of metals, soils were excavated and replaced. While providing Licensed Site Professional (LSP) services for the project, GZA pre-characterized and drafted disposal documentation for over 800,000 tons of soil removed from the site during building and site construction.

Waterfront Engineering: GZA was also responsible for the resilient design of the project’s waterfront marina, with over 600 linear feet of bulkhead and a 300-foot-long floating dock. Due to the soft soils at the site, a load-transfer platform was designed to support new loads and mitigate settlement concerns.

Benefit

At a total estimated design and construction value of $2.6 billion, the Encore Boston Harbor resort and casino is the largest single-phase private development in Massachusetts history. By nimbly responding to changes to the proposed project during construction, GZA was able to provide the multidisciplinary services and management skill required to help move this high-profile, technically-challenging project forward to an on-time completion date.

Insights

Comprehensive permitting/ ecological, marine, environmental and geotechnical services
Sediment sampling/analysis
Living Shoreline design
Remedial design and construction
Precharacterization program
LSP services
Geotechnical design for below-grade garage and 29-story tower
Design of floating dock, bulkhead, and load relief platform
Construction phase services
Sustainable and resilient design
2020 EBC James D.P. Farrell Award for Brownfields-Remediation Project of the Year

Massachusetts

Buildings & Real Estate Development

Water

Geotechnical Engineering Services

Environmental Site Investigation & Remediation

EHS Regulatory Compliance

Natural Resources and Ecological Services

Waterfront and Coastal Engineering

Construction Management

Data Management, Analytics and Visualization Solutions